It is known how to analyze cereal and oleaginous samples by spectrometric measurements in a near infrared mode, with view for example to determine their humidity, protein and oil percentage.
For this purpose, the sample is analyzed in the stationary state by means of analysis radiation by receiving a stabilized and collimated analysis radiation which is emitted by an emitter 100 positioned on one side of a readout chamber 300, before being received subsequently, via an optical diffraction system 400 by a receiver 500 located on the other side (FIG. 1).
The constraints on a movable spectroscopic measurement device for samples, lie in the requirement of perfect mechanical stability of the light source which should not deviate during possible vibrations and in the sequential flow of a constant volume sample in the readout chamber subject to the same vibrations. A regular flow of the sample allows regular homogeneity of the cereals. In the movable operation of such devices, it is difficult to find a remedy to the lack of natural homogeneity of the cereal or oleaginous sample in vibration. The grains which make up the sample are lightweight and different by their sizes. During its transport in a complex mechanism not adapted to the constraints of vibrations, the sample tends to be compacted, to no longer obey the laws of gravity by entanglement of the grains in a compact mass pressurized by the weight of the grains wainting above the others. Furthermore, the cereal varieties are different by their sizes, ranging from one millimeter in diameter for rapeseed to several millimeters for maize. Mechanically handling this size diversity in movement with a single mechanical system therefore proves to be difficult.
Another problem is having a correctly aligned light and having parallel rays for an analyzing of the sample which is flowing, in order to obtain consistent and accurate measurements. During a possible transport and/or vibrations, the alignment of the light tends to be maladjusted, the flow tending to not occur under a constant volume and the grains tending to be compacted and no longer being emptied from the device. Now, up till now, no satisfactory solution to this problem has been found.